426 



THE rO PILAR SCIENCE MONTHLY 



Las Cascadas Slide, ('ri.EiuiA Division, April, 1908. Area of Slide, 5,433 Square 



Yards. P^stimated ;i mount of material in motion, 100,000 cubic yards. 



Tliis slide started in the dry season and extended back 230 feet from 



the edge of cut and to within 50 feet of the crest of the hill. 



Mr. Biinau-Varilla^ a civil engineer who was at one time chief 

 enginee]-, of the Panama Canal Company, proposed a project with a 

 summit level at 130 feet ; l)ut with all locks so arranged that tliere 

 could he a gradual progress of excavation and deepening of the summit 

 level with a successive cutting out of locks until finally the lock canal 

 was converted into a sea-level canal. 



Major Gillette advocated a lock canal with its highest section at 100 

 feet above sea-level. 



The sea-level canal committee of the board of engineers reported in 

 favor of a canal 40 feet deep, with a bottom width of 150 feet in earth, 

 and side slopes adjusted to the nature of the ground so as to give a 

 surface width of 302 to 437 feet. The bottom width in rock was 

 to be increased to 200 feet and the surface width in rock was to be 

 208 feet. At the Pacific end tlie canal was to he protected by a tidal 

 lock located between Ancon and Sosa hills. The plans, as proposed by 

 the committee, included a dam at Gamboa across Chagres liiver of 

 either masonry alone or of earth and masonry combined. This dam 

 was necessary for the contiol of the river. 



The dimensions of the canal of the committee ])roject at the i^oint 

 of deepest cutting near Culebra are as follows : Bottom width, 200 feet ; 

 tlie hanks to have a hatter of 1 in 10 rising from the bottom to a berm 

 10 feet above the water snrface; the berm to he 45 feet wide (according 

 to diagram; 5(» feet according to text of report) ; then a succession of 

 bank slopes with a batter of 1 in 4 and a rise each of 30 feet, one above 

 the other, with intermediate hernis each 12i feet wide up to the rock 

 line — shown by a diagram for the ])oint known as Kilometer 54.41 in 



